The Valve,safety Relief, cataloged under National Stock Number 4820-01-531-6142, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 9 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-531-6142 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Connection Style | EXTERNAL SEAT FOR GASKET SEAL (BOSS) FIRST END |
| Connection Type | THREADED EXTERNAL BOSS FIRST END |
| Style Designator | STRAIGHT THRU W/BAFFLE |
| Material Document and Classification | MIL-P-25732 MIL SPEC SINGLE MATERIAL RESPONSE SEAT |
| Maximum Operating Temp | 275.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Material | ALUMINUM ALLOY BODY |
| Material | RUBBER BUTADIENE CLASS BR SEAT |
| Valve Operation Method | AUTOMATIC |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| D577A-2M-3 | 3/2 Design control — primary reference U.S. Government activity |
| D537A-2M-3 | 5/9 Secondary reference U.S. Government activity |
NSN 4820-01-531-6142 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 4820-01-551-6693. Verify interchangeability with system specifications before substitution.
Key specifications for 4820-01-531-6142: Flow Control Device: POPPET; Connection Style: EXTERNAL SEAT FOR GASKET SEAL (BOSS) FIRST END; Connection Type: THREADED EXTERNAL BOSS FIRST END; Style Designator: STRAIGHT THRU W/BAFFLE. 9 specifications are documented in the U.S. Government catalog.
No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.